/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: AbsolutePathPattern.java,v 1.2.4.1 2005/09/01 09:17:09 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GOTO_W;
import com.sun.org.apache.bcel.internal.generic.IF_ICMPEQ;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.ISTORE;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
import com.sun.org.apache.xml.internal.dtm.DTM;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
final class AbsolutePathPattern extends LocationPathPattern {

  private final RelativePathPattern _left; // may be null

  public AbsolutePathPattern(RelativePathPattern left) {
    _left = left;
    if (left != null) {
      left.setParent(this);
    }
  }

  public void setParser(Parser parser) {
    super.setParser(parser);
    if (_left != null) {
      _left.setParser(parser);
    }
  }

  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    return _left == null ? Type.Root : _left.typeCheck(stable);
  }

  public boolean isWildcard() {
    return false;
  }

  public StepPattern getKernelPattern() {
    return _left != null ? _left.getKernelPattern() : null;
  }

  public void reduceKernelPattern() {
    _left.reduceKernelPattern();
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    if (_left != null) {
      if (_left instanceof StepPattern) {
        final LocalVariableGen local =
            // absolute path pattern temporary
            methodGen.addLocalVariable2("apptmp",
                Util.getJCRefType(NODE_SIG),
                null);
        il.append(DUP);
        local.setStart(il.append(new ISTORE(local.getIndex())));
        _left.translate(classGen, methodGen);
        il.append(methodGen.loadDOM());
        local.setEnd(il.append(new ILOAD(local.getIndex())));
        methodGen.removeLocalVariable(local);
      } else {
        _left.translate(classGen, methodGen);
      }
    }

    final int getParent = cpg.addInterfaceMethodref(DOM_INTF,
        GET_PARENT,
        GET_PARENT_SIG);
    final int getType = cpg.addInterfaceMethodref(DOM_INTF,
        "getExpandedTypeID",
        "(I)I");

    InstructionHandle begin = il.append(methodGen.loadDOM());
    il.append(SWAP);
    il.append(new INVOKEINTERFACE(getParent, 2));
    if (_left instanceof AncestorPattern) {
      il.append(methodGen.loadDOM());
      il.append(SWAP);
    }
    il.append(new INVOKEINTERFACE(getType, 2));
    il.append(new PUSH(cpg, DTM.DOCUMENT_NODE));

    final BranchHandle skip = il.append(new IF_ICMPEQ(null));
    _falseList.add(il.append(new GOTO_W(null)));
    skip.setTarget(il.append(NOP));

    if (_left != null) {
      _left.backPatchTrueList(begin);

            /*
             * If _left is an ancestor pattern, backpatch this pattern's false
             * list to the loop that searches for more ancestors.
             */
      if (_left instanceof AncestorPattern) {
        final AncestorPattern ancestor = (AncestorPattern) _left;
        _falseList.backPatch(ancestor.getLoopHandle());         // clears list
      }
      _falseList.append(_left._falseList);
    }
  }

  public String toString() {
    return "absolutePathPattern(" + (_left != null ? _left.toString() : ")");
  }
}
